Here's the thing I find so bizarre about it, and yes everyone can be better and should be stretching and more flexible: how do you go from sitting a long time around the house, in computers, in other cars, etc (and I work out and have strong big lifts, etc) to riding in a car for an hour and the low back is strained? Clearly it has to do with the new position and cushion (I think it's this as others have said it on reddit commonly). It's not like it was a 5 hour drive. I've done those in other comfortable rides and not had symptoms. New seat is the problem, by definition.
I don't disagree, but my perspective is that a healthy spine or musculoskeletal system would not have a problem with an hour in a normal car seat.
For example, if several people had no difficulty with driving that car, but you did, it would shift the likelihood away from the seat and to the individual.
You can start troubleshooting from either direction, the person or the seat, but yes, the seat is easier to control as a variable.
There are few cars that have adjustments for pedal positions, but as you know steering wheel tilt, telescope, seatback angle, height, lumbar support and distance from the steering wheel are all adjustable.
However, you can also troubleshoot more difficult variables, such as odd factors that are causing you stress that "sets" your body into the car seat in an unusual way, perhaps with a certain rigidity that wears an isolated muscle group.
For example, since you're no spring chicken, if the car requires you to enter in an odd way that contorts your body, or maybe the entry makes you sort of fall into the seat in a way that compresses your spine a bit, then that could initiate unexpected physical stress.
